how to add forums oh topics

Hello everyone,,
My question is the following: I opened a grafiko design page, I mean, it is more about sportswear design

and I want https://batteryasking.com/best-trolling-motor-battery/ the users on the page to be able to create themes where they can upload images to show their shirts Oh designs that are possible when they create a forum oh only I can add forums not users

and in the forums you can add images,.